There are many different puplets out there now built on different versions of puppy Linux as well as the established builds. Computer specifications; how much ram and CPU speed are a big factor in choosing a puplet.

Once you have decided the best puppy OS to use, consider what you use your computer for and what your needs are. Then determine what to install on top of default apps. eg basic emailing, looking up websites like facebook, youtube, chatting online, and other general Internet use, creating documents, editing photos etc.

The size of your hard drive is not usually a problem for puppy Linux, neither is the flash drive size but the save file size (frugal install) you intend to use may be. Mostly with the save file you will not need more than 1-2GB but remember if you are installing puppy Linux on a flash drive that has a fat32 file system due to the limitations of fat 32 you can't save more than a 4GB save file. (Note that fat 32 is still good to use especially if you want to use the same flash drive to store you files on the go for access on any other computer.) It helps to have as little in the save file as you can. So what a lot of puppy users end up doing is saving things such as downloads, documents, music, photos etc, outside the save file, to hard drive or a flash drive.